There is known a self-optimizing control system comprising a search signal generator whose output is connected to a first input of a multiplier and a first input of an adder whose second input is connected via a final control element and an averaging filter to an output of the multiplier, an output of the adder being connected to an input of an object being controlled, while said object's output is connected to a second input of the multiplier.
The signal, applied to the input of the multiplier of the system under review, contains, apart form its useful component, harmonic components whose frequency is multiple to that of the search signal, whereas their amplitude is commensurable with that of the useful signal. Such harmonic components are, in fact, noise. A signal of a more complex spectrum is produced at the output of the multiplier.
The system under review is disadvantageous in its limited accuracy of control due to the presence of noise, and in its relatively low response due to the presence of the averaging filter intended for noise suppression, which, quite naturally, operates with a certain time lag.
There is further known a system for self-optimizing control of an object with a unimodal quality function. The accuracy of control and the response of this system are improved by interposing a band-pass filter between the object being controlled and the multiplier. It is only the fundamental harmonic which is separated from the object's output signal by the band-pass filter connected to the object's output. The fundamental harmonic is applied to the multiplier. At the multiplier's output there is produced a signal containing much less noise than in the case of the system described above. However, the signal at the output of the multiplier is not completely noisefree, which affects the accuracy and response of the system.